could I be pregnant ?

Em
Had sex 7 days before missing the pill for two nights although taking it due to severe vomiting/ gastro 
This sickness began on Thursday and I am now due for period on Tuesday 
Pre sure we used a condom but wouldn't rely on that as I was on the pill and he knew it
Should I be concerned ?
I know I should have made up the pills but I was so sick that there was no way to do this